Ultrasound imaging apparatus and method of controlling the same

Abstract

Provided is an ultrasound imaging apparatus including: an ultrasound probe including a transducer module including an ultrasound transducer array, a driving device configured to rotate the transducer module, a magnet configured to rotate as a result of rotation of the transducer module, and a position sensor configured to output one of a first signal and a second signal on the basis of a change in magnetic flux density according to rotation of the magnet; and a controller configured to determine a first time for which the first signal is output as the transducer module rotates in a first direction, control the driving device to switch the rotating direction of the transduce module from the first direction to a second direction at a first switching time point at which an output signal is switched from the first signal to the second signal, control the driving device to switch the rotating direction of the transducer module one or more times during a time corresponding to the first time with respect to a second switching time point at which the output signal is switched from the second signal to the first signal after the first switching time point, determine a second time for which the first signal is output after the second switching time point, and determine a backlash value on the basis of a difference value between the first time and the second time.

What is claimed is: 
     
       1. An ultrasound imaging apparatus comprising:
 an ultrasound probe including a transducer module including an ultrasound transducer array, a driving device configured to rotate the transducer module, a magnet configured to rotate as a result of rotation of the transducer module, and a position sensor configured to output one of a first signal and a second signal on the basis of a change in magnetic flux density according to rotation of the magnet; and 
 a controller configured to determine a first time for which the first signal is output as the transducer module rotates in a first direction, to control the driving device to switch a rotating direction of the transduce module from the first direction to a second direction at a first switching time point at which an output signal is switched from the first signal to the second signal, to control the driving device to switch the rotating direction of the transducer module during a same time as the first time, starting from a second switching time point at which the output signal is switched from the second signal to the first signal after the first switching time point, to determine a second time for which the first signal is output after the second switching time point, and to determine a backlash value on the basis of a difference value between the first time and the second time, 
 wherein the position sensor switches the output signal from the second signal to the first signal when the magnetic flux density reaches a first magnetic flux density as the magnet moves toward the position sensor, and switches the output signal from the first signal to the second signal when the magnetic flux density reaches a second magnetic flux density as the magnet moves away from the position sensor, wherein the first signal and the second signal are different from each other due to the position sensor's hysteresis characteristics, and 
 wherein the controller determines a third switching time point, which is a time point before the first switching time point, at which the output signal is switched from the second signal to the first signal as the magnet moves toward the position sensor as a result of the transducer module rotating in the first direction, and determines a time difference between the third switching time point and the first switching time point to be the first time. 
 
     
     
       2. The ultrasound imaging apparatus of  claim 1 , wherein the controller determines the backlash value by dividing the difference value between the first time and the second time by a number of times the rotating direction of the transducer module is switched during the same time as the first time, starting from the second switching time point. 
     
     
       3. The ultrasound imaging apparatus of  claim 1 , wherein the controller controls the driving device to rotate the transducer module in one of the first direction and the second direction within a preset time from the second switching time point at which the rotating direction of the transducer module is switched, during the same time as the first time, starting from the second switching time point. 
     
     
       4. The ultrasound imaging apparatus of  claim 1 , wherein the controller determines a fourth switching time point, which is a time point after the second switching time point, at which the output signal is switched from the first signal to the second signal as the magnet moves away from the position sensor as a result of the rotating of the transducer module after the same time as the first time, starting from the second switching time point, and determines a time difference between the second switching time point and the fourth switching time point as the second time. 
     
     
       5. The ultrasound imaging apparatus of  claim 1 , wherein the driving device further includes:
 a motor configured to generate a rotating power for rotating the transducer module; and 
 a transmission device configured to transmit the rotary power of the motor to the transducer module, 
 wherein the controller controls the motor to rotate at a preset speed. 
 
     
     
       6. The ultrasound imaging apparatus of  claim 1 , wherein the controller controls the ultrasound probe to determine the backlash value when the ultrasound probe is connected to a main body of the ultrasound imaging apparatus. 
     
     
       7. The ultrasound imaging apparatus of  claim 1 , further comprising an inputter configured to receive an input from a user,
 wherein the controller controls the ultrasound probe to determine the backlash value in response to receiving the input about photographing a three dimensional (3D) ultrasound image through rotation of the transducer module from the user, or receiving the input about determining the backlash value. 
 
     
     
       8. The ultrasound imaging apparatus of  claim 1 , wherein the controller controls the ultrasound probe at preset time intervals to determine the backlash value. 
     
     
       9. The ultrasound imaging apparatus of  claim 1 , further comprising:
 a display configured to display an ultrasound image, 
 wherein the controller controls the display to output a notification or controls the ultrasound probe to determine the backlash value again when the backlash value exceeds a preset threshold value. 
 
     
     
       10. The ultrasound imaging apparatus of  claim 1 , wherein the controller, when controlling the driving device to switch the rotating direction of the transducer module, controls the driving device to output a rotary power in one of the first direction and the second direction during a time extended from a preset time by a delayed time corresponding to the backlash value. 
     
     
       11. The ultrasound imaging apparatus of  claim 1 , wherein the controller shifts a rendering image corresponding to the first direction and a rendering image corresponding to the second direction from a central axis of the transduce module in directions corresponding thereto by an angle, by which each rendering image the first or second direction is shifted for a delayed time corresponding to the backlash value, to generate a result rendering image of the ultrasound image. 
     
     
       12. The ultrasound imaging apparatus of  claim 1 , wherein the controller determines a time difference between the first switching time point and the second switching time point as a third time, and determines an error time shortened by a delayed time corresponding to the backlash value from the third time due to hysteresis characteristics of the position sensor. 
     
     
       13. The ultrasound imaging apparatus of  claim 12 , wherein when a first point of time, at which the output signal is switched from the second signal to the first signal as a result of the transducer module rotating in the first direction, is set as a central axis of the transducer module, the controller determines a shifted point of time shifted, in the first direction for the error time, from a second point of time, at which the output signal is switched from the first signal to the second signal as a result of the transducer module rotating in the second direction, as the central axis of the transducer module, so that the shifted point of time matches the first point of time. 
     
     
       14. A method of controlling an ultrasound imaging apparatus comprising an ultrasound probe including a transducer module including an ultrasound transducer array, a driving device configured to rotate the transducer module, a magnet configured to rotate as a result of rotation of the transducer module, and a position sensor configured to output one of a first signal and a second signal on the basis of a change in magnetic flux density according to rotation of the magnet, the method comprising:
 determining a first time for which the first signal is output as the transducer module rotates in a first direction; 
 controlling the driving device to switch a rotating direction of the transduce module from the first direction to a second direction at a first switching time point at which an output signal is switched from the first signal to the second signal; 
 controlling the driving device to switch the rotating direction of the transducer module during a same time as the first time, starting from a second switching time point at which the output signal is switched from the second signal to the first signal after the first switching time point; 
 determining a second time for which the first signal is output after the second switching time point; and 
 determining a backlash value on the basis of a difference value between the first time and the second time, 
 wherein the position sensor switches the output signal from the second signal to the first signal when the magnetic flux density reaches a first magnetic flux density as the magnet moves toward the position sensor, and switches the output signal from the first signal to the second signal when the magnetic flux density reaches a second magnetic flux density as the magnet moves away from the position sensor, wherein the first signal and the second signal are different from each other due to the position sensor's hysteresis characteristics, and 
 wherein the determining of the first time comprises: 
 determining a third switching time point, which is a time point before the first switching time point, at which the output signal is switched from the second signal to the first signal as the magnet moves toward the position sensor as a result of the transducer module rotating in the first direction; and 
 determining a time difference between the third switching time point and the first switching time point. 
 
     
     
       15. The method of  claim 14 , wherein the determining of the backlash includes determining the backlash value by dividing the difference value between the first time and the second time by a number of times the rotating direction of the transducer module is switched during the same time as the first time, starting from the second switching time point. 
     
     
       16. The method of  claim 14 , further comprising controlling the driving device to rotate the transducer module in one of the first direction and the second direction within a preset time from the second switching time point at which the rotating direction of the transducer module is switched, during the same time as the first time, starting from the second switching time point. 
     
     
       17. The method of  claim 14 , wherein the position sensor switches the output signal from the second signal to the first signal when the magnetic flux density reaches a first magnetic flux density as the magnet moves toward the position sensor, and switches the output signal from the first signal to the second signal when the magnetic flux density reaches a second magnetic flux density as the magnet moves away from the position sensor.